Introduction:
In cPanel linked nodes, two or more servers (nodes) are connected each other via WHM’s Link Server Nodes interface: WHM > Home > Server Configuration > Link Server Nodes.
This feature allows the optimization primary (parent node) node’s resource usage by distributing functionality across various nodes.
For ex; you can allocate a cPanel account’s mail functionality to a secondary server (child node) optimized for mail. As a result, your primary node’s resource usage is on the lower side. This gives the best user experience for non–mail services, such as web hosting.
Server Profiles
You can optimize your child nodes to set a server profile. You can configure a node’s profile directly in WHM’s server profile interface: WHM > Home > Server Configuration > Server Profile.
Note: The parent node in a linked node configuration uses a Standard server profile. A parent node can’t use any other server profile. Check this documentation for server profiles guide: How to Use Server Profiles
Parent and child nodes
Linking nodes together develops a “parent and child” node configuration. For example;
- While configuring, the parent node is an authoritative controller. This type of node allocates tasks to one or more child nodes.
A child node is a non-authoritative node that commands tasks from the parent node. For example, a child node is configured to handle mail–related functions for accounts on the parent node. To read more check Link Server Nodes interface documentation.
Child node restrictions
The following restrictions apply to all child nodes on a linked node configuration:
- cPanel users are not able to log in directly to cPanel on a child node. They have to log in to cPanel via the parent node.
- You must call APIs on the parent node, which proxies requests to the child node.
- The system blocks all cPanel API calls on the child node.
- The system blocks WHM API functions that call a distributed cPanel account on the child node.
- You can allocate one child node to a cPanel account when offloading a particular function to the account. However, a parent node can have more than one child node that manages a particular function. For example, the system supports a parent node with two child nodes that allow handling both mails simultaneously. The system doesn’t support a cPanel account using two child nodes for its mail function.
- We don’t support configurations that link more than one parent node to a single child node.
- You can link to parent node to a child node that utilizes the same major version or later of cPanel & WHM.
The following restrictions apply to only mail child node on a linked node configuration:
- cPanel users should log in to their Webmail accounts using the Webmail subdomain. For example, the https://webmail.example.com URL instead of https://example.com:2096
- An allocated cPanel account’s mail and webmail subdomains resolve to the child node.
- You are not able to enable IPv6 on a cPanel account if you want to access those accounts to a mail node.
- Ask your web hosting provider to enable the API Tokens for the linked cPanel account in WHM’s Feature Manager interface: WHM » Home » Packages » Feature Manager.
- You can use DNS Domain Control Validation DCV.
- In the case of AutoSSL or SSL Certificates which are purchased via your cPanel account, your cPanel & WHM nodes must be able to manage the authoritative DNS server.
User access and security on a child node
Important to note:
Server profiles come with performance improvements, not necessarily additional security.
Distributed accounts possess an equal level of access on the child node as they perform on the parent node. This access helps to link nodes to work smoothly with existing systems.
For ex, disabling the Pipe to a Program option in cPanel’s Forwarders interface: cPanel » Home » Email » Forwarders. cPanel doesn’t support email forwarders that execute programs. Users can manually create these forwarders. However, they don’t preserve this function for future versions. They are looking for a transition to lower the access security model in a future version.
cPanel accounts and linked nodes
A cPanel account that discharges particular functions (such as mail) to a child node is called a distributed cPanel account. This basic process consists of the following steps:
- The system develops two versions of the account one is on a parent node and one on a child node.
- The system moves the desired functionality for mail services from the account on the parent node to the account on the child node. The account available in the parent node manages all other functions easily.
Important:
AutoSSL certificate on allocated accounts needs DNS Domain Control Validation for protecting the website.
To monitor all allocated cPanel accounts on a child node, click View Distributed Accounts in WHM’s Link Server Nodes interface: WHM » Home » Server Configuration » Link Server Nodes
Creating distributed accounts
While creating a new account in WHM’s Create a New Account interface: WHM » Home » Account Functions » Create a New Account. You can select how to distribute the account. For ex, to allocate the new account’s mail, use the Mail Routing Section to allocate the child node on which the account’s mail will reside.
Make an existing account a distributed account
To distribute an existing account, use the Linked Nodes section in WHM’s Modify an Account interface: WHM » Home » Account Functions » Modify an Account. The system will create the rectify the account on the child node as part of this process and discharge the desired functionality to the child node’s version of the account.
Note: If you make a change in the cPanel account to use a mail child node, the system copies the account’s existing mail to that child node. Once the system successfully allocates the account, it removes the account’s mail stored on the parent node.
Distributed accounts on a linked mail child node
In most of cases, all IMAP, POP3, and SMTP traffic for distributed cPanel accounts goes to the mail child node. For ex, cached DNS checkup, the parent mode will:
- Develop a proxy IMAP and POP3 connections to the mail child node.
- Reroute SMTP mail delivery to the mail child node.
Warning:
The following instructions are useful for distributing cPanel accounts on a mail child node:
- They disable the Pipe to a Program option in cPanel’s Forwarders interface: cPanel » Home » Email » Forwarders.
- They don’t support email forwarders that execute programs. Users are allowed to create these forwarders. However, they don’t preserve this function in future versions.
Managing distributed accounts
Important
Only system administrators are allowed to perform these actions. Users can manage distributed cPanel accounts using one of the following methods:
Transfer accounts that have been distributed to a linked server
Note:
To understand important information on linked node restricted read the Parent and Child nodes section of this document.
If you’re looking to transfer a distributed account from one parent/child pair to another parent/ child pair, use WHM’s Transfer Tool interface: (WHM » Home » Transfers » Transfer Tool) to perform this action.
If you want to transfer a distributed account to a new parent node while keeping the account on the same child node, execute the below-given action:
- Dedistribute all of the accounts from the child node. Utilize the Link Server Nodes section in WHM’s Modify an Account interface: (WHM » Home » Account Functions » Modify an Account) to execute this action.
Note: You can read this document Undoing Account Distribution for more information. The account needs to be fully dedistributed before it can be redistributed to the child node.
- Unlink the child node from the old parent node. Use WHM’s Link Server Nodes interface: WHM » Home » Server Configuration » Link Server Nodes) to execute this action.
- Migrate the account from the old parent node to the new parent node with WHM’s Transfer Tool.
- You’ve to link the child node to the new parent node. Next, you’ve to select Mail Node under the account configuration options in WHM’s Transfer Tool to allocate the child node to the new parent (standard profile) node.
- Redistribute the accounts to the child node. Utilized the Linked Server Nodes section in WHM’s Modify an Account interface: WHM » Home » Account Functions » Modify an Account) to execute this action.
Distributed Reseller Accounts
Distributed reseller accounts don’t have their reseller privileges on the child node. Due to this, allocated reseller accounts can’t log in to WHM on a child node.
Reseller–owned accounts
When a distributed reseller develops a cPanel account, the new account users are allowed to use the same distribution status as the reseller: distributed or not distributed. However, if the reseller account’s distributed status changes, its cPanel accounts also remain the same.
For ex, a distributed reseller develops a new Cpanel account. Later, the server administrator dedistributes the reseller account to the parent nodes. Ahead, all reseller-owned accounts will be distributed to the child node unless the server administrator updates those accounts’ distribution status.
Note:
If any of the distributed reseller’s cPanel accounts’ distribution status changes, the reseller’s distribution status remains the same.
Password management
In linked nodes, there are a few things that need to be considered for distributing cPanel account passwords:
- A child node’s password strength configuration influences passwords that relate to the functions the child node serves. For ex, if an account’s mail is given, the child node controls only that account’s email account and mailing list password strength settings. The parent node manages the rest of password strength settings (for ex, FTP and cPanel account passwords)
- An account’s password age on the parent node and child node will not match when you update this setting on the parent node.